Chapter Thirteen
Gradient Mesh
In this chapter we are going to expand on our knowledge of gradients - learning to use the Gradient Mesh Tool to create some stunning 3D effects.
Step by Step
Earlier in this tutorial we looked at using a gradient in different ways to create a “3D effect” - simple shadows and reflections.
A Gradient Mesh takes this one step further and starts to look at photo-realism, or making art and illustrations look like they are photographs.
To demonstrate this we are going to create a simple gradient mesh ourselves.
To begin, import the file titled “Cherry for Gradient Mesh” into illustrator from the Tutorial Folder. Resize the image as you wish and then lock the layer using the Layers Palette to prevent it from being accidentally moved or edited.
Example Showing Gradient Mesh - By Aisling Walsh and available from here.
One of the first things we are going to do is recreate the outline of one of the
cherries. However, despite what we have learnt about the Pen Tool we are
not going to use this - instead we are going to recreate the shape using basic
shapes such as a circle or a square. This is because when you use the pen tool
the mesh line created later by the gradient mesh tool is not smooth, and we want
our final effect to be very smooth to replicate the cherries.
1) Go to Window>Navigation to open a preview box. This
will be useful when we are working in “outline” mode. To
move your preview window out of the way, simply “dock” it
onto your Floating Palette and minimise it.
2) Create a new layer on the Layers Palette, and on that
layer create a rough circle over the shape of one of the
cherries.
3) Now, select your circle and select the “Gradient
Mesh Tool from the Tool Bar. Use the tool to click on
the point in the centre of your circle.
4) This inserts a few more “nodes” or points onto your circle.
Using the gradient tool or the direct selection tool, adjust
these until you are reasonably happy that the shape of
your cherry has been mimicked. To help you to create an
accurate outline, go to your layers palette and Ctrl-click on
the eye shape next to the layer your circle is on. This will
toggle the “Outline Mode” of that particular layer, leaving
your cherries still visible.
If you double click on your layer you can change its colour,
making the lines easier to see. For example, I changed my
layer colour to green.
5) Once you are happy with your outline you can start adding more lines to your mesh, increasing the accuracy of your shape. You should have more lines where the colour of your shape changes more rapidly, for example, where there are areas of shadow or highlight. As you can see on the right, I’ve done this around the edges of my cherry shape.
If you want to remove any mesh lines, simply hold down the
Alt button and click on the line you wish to remove.
6) Once you are happy with your mesh, it is time to start applying colour.
There are two methods of doing this. The first is to create a colour palette of a few colours you will use for your main colour, then a colour for your shadow and highlight for each colour in your image.
The method we will use is more accurate however - producing a better “Photorealistic” final image.
Open your Navigation Palette. It should show a large, coloured shape directly over your cherry, like the image to the right.
First, you will need to select the “Eyedropper” Tool from the Toolbar. If you hold down the Ctrl button, the tool will switch to the direct selection tool. Hold down the Ctrl button and select one of the points near the bottom of your mesh.
7) Let go of the Ctrl Button and then select a point on the cherry image close to the point you have selected. you should then see, in your navigation pane, a small area of the cherry colour appear. If not - don’t worry! it just means the area that has changed colour is too small to display.
Continue selecting points and changing their colour using the Eyedropper Tool. As you do this, more of your image in the navigator window will change colour.
8) Continue selecting points and colours until you have a completely coloured cherry.
Once this is complete Ctrl Click on the eye shape in the layers palette again to see your cherry. Now is the time for editing your mesh. As you can see, the highlight on the cherry to the left is not as sharp as the real image, and we need to improve that. To do so, we need to add some more mesh lines around the highlight to sharpen the blend between colours.
9) Once you have added new mesh lines you can shape them around the highlight. If you need to move the handles independently of one another, select the “Anchor Point Tool” from the tool bar. As you can see in the image to the right I have created a circle around the highlight. I have then coloured the points using the Eyedropper Tool to create a more realistic effect. This can then be replicated for the darker patch on the skin of the cherry and glossy reflections.
10) Once you have completed the cherry continue on and use the same method to create the other cherry, the stem and the joint between the two stems at the top. Additionally, you could add the shadow beneath them, unless you want to leave them floating. To help, you can lock the cherry that you have completed and hide it using the layers panel.
11)When you have completed your cherries they should
look similar to the image on the far right -
Cherry
Gradient Mesh
If you put the layers into outline mode
(Press Ctrl-Y to make all layers go into
outline mode, and to take all layers
out of outline mode) they should look
similar the image on the near right.
Creating photorealistic images using
this method is a good way to create
a vector that can be scaled if the only
image you have is very small and of
low quality.
